Diana Kimpton 
Princess Ellie to the Rescue [EPUB ebook] 

Princess Ellie is pony-mad! And she’s fed up with being a princess! She hates soppy pink dresses and boring waving lessons. She’d much rather be riding one of her four gorgeous ponies, or even mucking out the royal stables. But someone is spying on her – a mysterious stranger who doesn’t want to be seen. Then disaster strikes, and Ellie’s sure the girl in the woods must be to blame. Can she solve the mystery and she rescue her beloved Sundance before it’s too late?